1. Field of the Invention
The present invention relates to a road profile defining apparatus, a road profile defining method, and a road profile defining program.
2. Background Art
The present invention relates to a road profile defining apparatus, a road profile defining method, and a road profile defining program.
In recent years, in order for a vehicle to travel safely on the road with a gradient, a technique of detecting the situation of the road along which the vehicle is traveling has been proposed. Using this technique, as a situation of the road, gradient information indicating whether the road is uphill or downhill is detected.
For example, in a road information extraction method disclosed in JP-A-2002-366936 (Patent Document 1), a target object is detected from an image acquired by a camera mounted in a vehicle, and a horizontal estimation distance to the detected target object is calculated. Then, the vertical azimuth at which the target object is located on the circumference and the radius of curvature of the circumference is calculated, and the actual distance to the target object is calculated based on the radius of curvature and the vertical azimuth which have been calculated.
In addition, a road shape detection apparatus disclosed in JP-A-2010-40015 (Patent Document 2) includes lane marking extraction means for extracting image portions of the left and right lane markings, which separate the lane of a vehicle, from an image in front of the vehicle captured by a camera and road shape detection means thr calculating, for the image portions of the lane markings, a tangential line in a place within a predetermined range from a place whose position on corresponding real space is closest to the vehicle and detecting the gradient of the lane of the vehicle based on a deviation between each image portion of the lane markings in the Y-axis direction equivalent to the travel direction of the vehicle and the tangential line.